Field of the Invention
The present invention relates to a technique in which a specular reflection component in a captured image is detected using a polarizer, and image processing is performed according to the detection result.
Description of the Related Art
Conventionally, a specular reflection component has been removed using a polarizer when capturing an image. For example, when capturing a landscape such as that shown in FIG. 16A, in the case where a camera 1601 captures a scene in which light from a sun 1602 is reflected by the surface of a lake 1604 as shown by a reflection area 1605, the reflection on the surface of the lake is adjusted using a polarizer (PL filter) 1606 as shown in FIG. 16B when performing capturing.
On the other hand, Japanese Patent Laid-Open No. 2010-266730 discloses a method in which a polarizer having mutually different polarization characteristics is placed at the pupil position of a lens, and the polarization state is detected by using a polarizing beam splitter or the like to separate the resulting polarized light in accordance with the polarization when performing capturing. Similarly, Japanese Patent Laid-Open No. 2009-162847 discloses that different polarized images are captured by using multiple polarizers having mutually different polarization directions over the image sensor. Also, Japanese Patent Laid-Open No. 2012-199614 discloses a method in which multiple light receiving elements are provided for each microlens over the image sensor, and AF or the like is performed by dividing the light flux over the pupil.
However, in image capturing that employs conventional polarizers, capturing needs to be performed multiple times in order to check the polarization component, and this is not suited to the capturing of a moving body or the like. Also, in the conventional technology disclosed in Japanese Patent Laid-Open No. 2010-266730, a polarizing beam splitter and multiple image sensors are needed in order to divide the polarized light flux, thus leading to the problem that the structure becomes complex. Also, in Japanese Patent Laid-Open No. 2009-162847, complex polarizers need to be formed over the image sensor surface.